Notions with respect to what is and is not a violation of privacy of an individual have drastically changed over time. For instance, years ago taking a photograph of a specific person without the knowledge and consent of that person was thought to be a violation of the privacy of that person. In contrast, given the proliferation of digital cameras, most individuals do not deem a photograph that includes them as an invasion of their privacy. In another example, at one time people, in general, felt that the idea of a telephone ringing in their home was invasive of their privacy. Today, portable telephones often ring in pockets of individuals, and in general people do not give a second thought to privacy when a telephone rings.
Currently, large amounts of data can be collected with respect to individuals that perform searches by way of a search engine or service. For instance, information can be captured regarding a user's location, IP address, previous searches, time that searches are performed, day of week that searches are performed, and/or the like. Collection, analysis, and/or retention of this type of data may, for a particular user, bring about concerns relating to privacy. For instance, given a certain amount of information about a user, such user may become identifiable or their identity may be one of a relatively small set of users. Once a person is identified or can be identified, information such as what types of websites they visited, queries provided, time that searches were performed, and the like can be associated with the identified user, which typically will not be desirable to the user.
From a different perspective, however, information collected with respect to a user can improve operation of a search engine with respect to the user. This type of information, as well as other information about context, interests, and goals of a user can be used to enhance web search. For example, knowledge of a searcher's location can be useful in identify informational goals when the user inputs queries such as “pizza” or “sports”.